1. Field of the Invention
This invention relates to extensible torque bars of the type used for driving socket wrenches and like devices.
2. Prior Art
In the use of wrenches, e.g. ratchet wrenches, and the like it is often necessary or convenient to have an elongated member through which a torque may be transmitted at a distance between its source of application and the tool immediately applying the torque. Since the need for such a member may arise in many different situations, it is desireable to have a device wherein the length of the member may be varied. This general type of tool, i.e. an extensible torque bar, is known to persons skilled in the art.
Such an extensible torque bar must be readily adjustable to a desired length and must also be capable of transmitting an applied torque without damage to the bar itself. If it also desireable to provide an extensible torque bar which, by simple and convenient manipulation may be lengthened or shortened to any desired length between a minimum and maximum. Such variation in the length of the bar is essential in order to gain access to machine parts at different locations on the machine. It is also highly desireable to have an extensible torque bar which can be adjusted without removing it from the machine part, for example, a nut being tightened or loosened. Thus the means for extending or retracting the torque bar should be easily accessible to the user.
Extensible torque bars and similar devices are known in the art. For example, the following U.S. patents are directed to extensible torque bars or tool shanks;
U.S. Pat. No. 2,438,633 to Condor; PA1 U.S. Pat. No. 2,963,930 to Clothier et al; PA1 U.S. Pat. No. 3,227,015 to Tremblay; and PA1 U.S. Pat. No. 3,306,639 to Lyon. PA1 U.S. Pat. No. 2,520,652 to Pfauser et al; PA1 U.S. Pat. No. 2,592,987 to Trimboli; PA1 U.S. Pat. No. 3,188,895 to Jones; and PA1 U.S. Pat. No. 4,070,932 to Jeannotte.
All of these devices cannot be adjusted while the driven tool, e.g. the socket wrench, is in place. The tool must be taken off, for example, the bolt to extend or retract the device. Additionally, the devices do not provide an infinite variation of length between their minimum and maximum extensions i.e. there are definite finite positions on the device between minimum and maximum extensions.
Additionally, of interest are the following U.S. patents:
All of these relate to tools which may be extended but do not relate to extensible torque bars or tools shanks.